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Al
2-Apr-11, 07:00 PM
I have some paper skirt templates from BBV and I'm not sure about the chip bag template.

The pressure segments are about 6 inches wide at the hull attachment point and they taper out to about 8 inches wide at around the ground contact area.

the template BBV have sent for the chip bags have extra below the normal skirt segment, with a cut line up the middle and a few inches on ground contact area. as can be seen in the picture below.

6117

If I follow the bottom of the template and then sew up the seam as in the constructors guide then the bag will be too narrow.

My way of thinking is that the chip bag will be tapered as per pressure segments, so the extra below the normal segment will be 3" + seam at the ends ( J ), then 4" + seam in the middle ( I ) where the cut line is indicated.

I'm not sure if this is correct so looking for guidance please

Al

Bill Baker
3-Apr-11, 11:35 AM
[QUOTE=Al;73182]I have some paper skirt templates from BBV and I'm not sure about the chip bag template.

The pressure segments are about 6 inches wide at the hull attachment point and they taper out to about 8 inches wide at around the ground contact area.

the template BBV have sent for the chip bags have extra below the normal skirt segment, with a cut line up the middle and a few inches on ground contact area. as can be seen in the picture below.

6117

If I follow the bottom of the template and then sew up the seam as in the constructors guide then the bag will be too narrow.

My way of thinking is that the chip bag will be tapered as per pressure segments, so the extra below the normal segment will be 3" + seam at the ends ( J ), then 4" + seam in the middle ( I ) where the cut line is indicated.

I'm not sure if this is correct so looking for guidance please

Al to take your points.

you were sent two patterns and an old sewn up segment,

The first, standard pattern if sewn up, will make an un-pressured segment.

If you wish to make a pressure segment it will be necessary to sew the insert along the lines marked on the pattern,
E.G. the 6" end is sewn at the attachment point and the other wider end finishes near the tongue, not the contact area where it will hang loose acting as a valve in operation - similar to the segment provided.

Sew the Chip bag skirt as advised E,G, fold the segment in half and sew along the full length J to J and cut as directed - sew the rest as a normal skirt.
As the chip bags go round the rear corners the attachments are closer together so at this point the bottom panel will be narrower whereas at the contact point it will be 6" wide

The Constructor's Guide was produced 25 + years ago and is exactly that - a Guide. If you have a specific problem with a specific design of craft I suggest you phone the builder, as in small ways continuous development takes place in many areas on any craft, which is why when you indicated that you wished to race this craft, Rupert supplied you with the latest racing skirt technology rather than a skirt suitable for an historic exhibit which in some ways is what the hull is.

We hope to get up to one of your Scottish cruises during the summer in order to spend your Scottish fiver.

Please do not hesitate to phone if you need further help.
Regards Bill

Al
3-Apr-11, 01:09 PM
Thanks Bill